Where you can watch

The service is called Jellyfin (that's the app you'll look for in app stores). It works basically everywhere:

In a web browser (easiest) Go to https://jellyfin.theduckynerdball.com and sign in. Works on any computer.

On your phone or tablet Install the free Jellyfin app (App Store / Google Play). On first launch it asks for a server address — enter:

https://jellyfin.theduckynerdball.com

Then sign in with your username and password.

On a TV There's a free Jellyfin app for Roku, Fire TV, Android TV / Google TV, and most smart TV platforms. Install it, and when it asks for the server address, enter the same address as above, then your login.

Everything syncs — start a movie on the TV, finish it on your phone, and it remembers where you were.